MAIDUGURI, Nigeria, Dec 26 (Reuters) - A suicide bomber attacked a cattle market on Monday in Maiduguri in northeastern Nigeria, the city worst hit in the seven-year insurgency waged by Islamist militant group Boko Haram.

The police said the female bomber, who struck the Kasuwan Shanu market in the central district of Kasuwa, was the only person killed in the blast at about 08:40 a.m. (0740 GMT).

In a statement, police said a second woman who had a bomb was “lynched by an irate mob in the vicinity.” Security forces later detonated her device.

Nobody has claimed responsibility for the attack but it bears the hallmarks of Boko Haram and comes days after President Muhammadu Buhari said the jihadist group’s key camp in its last remaining enclave had fallen.

Buhari said the fall of the camp in the group’s Sambisa forest base after an offensive by Nigeria’s army in the former colonial game reserve marked the “final crushing of Boko Haram.”

Despite having been pushed back to the forest by the army in recent months, the group still stages bombings in the northeast and in neighboring Niger and Cameroon. A suspected Boko Haram suicide bomber killed two people in Cameroon on Sunday.

The Islamist militant group has killed 15,000 people and displaced more than two million during a seven-year insurgency to create an Islamic state governed by a harsh interpretation of sharia law in the northeast of Africa’s most populous nation.